This disclosure relates to gas flow measurement equipment and, in particular, to equipment, systems, and methods designed to improve the accuracy of gas flow measurement used in custody transfer transactions along a gas pipeline.
Because of the tremendous volume of gas being transferred between pipeline companies, small measurement errors can have very large financial effects. Therefore, ultrasonic gas flow meters used in gas pipelines must be calibrated from time-to-time. However, doing this calibration requires shutting down flow through the pipeline, removing the meter run from the line, and sending the meter run to a calibration laboratory that makes use of a reference bank of meters. See FIG. 1.
Until the calibrated meter run is returned from the laboratory, which is typically a week or more, and reinstalled in the line, no gas is flowing through the line. The cost and lost revenue associated with this shutdown prevents many pipeline owners from calibrating the meter as often as it should be calibrated.